Last week, six very healthy men suddenly wound up in a London hospital in critical condition. Earlier this month, 11 otherwise well people tested positive for tuberculosis, according to Montreal’s health department. What do these people have in common? All were human subjects in research paid for and conducted by private companies. These mishaps mean that the time has come to take a closer look at how commercialized research involving human subjects is being conducted all over the world.

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The people in England were involved in a study of an experimental leukemia drug. It was paid for by a German pharmaceutical company but run by a U.S. company, Parexel. In Montreal, volunteers apparently caught TB from an infected subject they'd been housed with as part of a study paid for by a Canadian company but administered by another U.S. research company, SFBC International.

It's certainly true that human research is risky business. Even when people are in safety studies and only exposed to relatively small doses of experimental drugs, things can go terribly wrong. That's why it's so important for healthy volunteers who are recruited into clinical research to fully comprehend the reality that there are real risks involved in biomedical research. And it's equally important that those who conduct these studies — drug companies, contract research organizations and the review committees who by U.S. law must approve all human trials before they can begin — put the informed consent and safety of subjects first. There are reasons to think this didn't happen in either the British or Canadian trials.

In the case of the British subjects, who went into acute organ failure and suffered excruciatingpain immediately after being exposed to a new substance intended to fight some forms of cancer, some doctors are outraged that the study was allowed to even start given that there had been previous problems in animals and people with very a very similar substance.

The recruitment of the participants into the British trial certainly left much to be desired ethically. As Bloomberg News reported, the Web site which announced the opportunity to enroll in the study for healthy volunteers said almost nothing about risks but went on and on about good pay, free medical care, free food and "plenty of time to read or study or just relax, with digital TV, pool table, video games, DVD player and free Internet access.'' This is not the sort of language that tells people eager to make some easy money that they are entering into the risky world of high-stakes medical research.

SFBC has also had its share of ethical missteps beyond the problems in Montreal. Bloomberg also reported that the company’s major facility for housing subjects in long-term studies in Miami, Fla., had received numerous safety and fire code violations. When subjects went public with complaints about problems they had seen at SFBC’s Miami testing facility, at least three of them said they were bullied and threatened with deportation by SFBC officials.

Twenty years ago most clinical research was conducted in academic medical centers. American companies did their research in the United States. Most research was paid for by government money. All that has changed.

Today private companies pay for the bulk of clinical research on new drugs, medicines and devices. They hire private companies to run their studies and to review them. And a lot of this research is done using poor people or students, sometimes in the United States but often in Europe, India and Southeast Asia.

The business of conducting medical research is profitable. Private companies running studies for pharmaceutical and device companies are now a $14 billion industry in the United States alone.

The problem with the intense commercialization of research is that it's not clear that contract research organizations such as Parexel and SFBC that make their living meeting deadlines for drug company sponsors always put subject welfare first. There is plenty of room for conflicts of interest when the person recruiting volunteers for research is being paid to get subjects enrolled and data generated as quickly as possible.

The recent events in London and Montreal make it clear that it is time for Congress and other regulatory bodies here and overseas to take a hard look at how clinical research is being done these days. Many of those in the for-profit business of conducting clinical research may be doing their best, but they and their sponsors had best be putting the safety and welfare of their subjects first. Otherwise they should have no business doing clinical research.

Arthur Caplan is director of the Center for Bioethics at the University of Pennsylvania.